Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) for the determination of [Zn2+] in estuarine waters

View/ Open
Issue date
2016-03-17Author
Pearson, Holly B. C.
Braungardt,Charlotte B.
Worsfold,Paul
Comber, Sean
Suggested citation
Pearson, Holly B. C.;
Galceran i Nogués, Josep;
Companys Ferran, Encarnació;
Braungardt,Charlotte B.;
Worsfold,Paul;
Puy Llorens, Jaume;
Comber, Sean;
.
(2016)
.
Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) for the determination of [Zn2+] in estuarine waters.
Analytica Chimica Acta, 2016, vol. 912, p. 32-40.
https://doi.org/10.1016/j.aca.2016.01.035.
Metadata
Show full item recordAbstract
Zinc (Zn) has been classified as a 'Specific Pollutant' under Annex VIII of the EU Water Framework Directive by two thirds of the EU member states. As a result, the UK Environmental Quality Standard (EQS) for Transitional and Coastal (TrAC) Waters has been reduced from 612 nM to 121 nM total dissolved Zn. It is widely accepted that the free metal ion ([Zn2+]) is the most bioavailable fraction, but there are few techniques available to determine its concentration in these waters. In this work, Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) has been applied, for the first time, to determine [Zn2+] in estuarine waters. The AGNES method had a mean RSD of +/- 18%, a (deposition time dependent) limit of detection of 0.73 nM and a [Zn2+] recovery of 112 +/- 19% from a certified reference material (BCR-505; Estuarine Water). AGNES results for 13 estuarine samples (salinity 0.1-31.9) compared well (P = 0.02) with Competitive Ligand Exchange Cathodic Stripping Voltammetry (CLE-AdCSV) except for one sample. AGNES requires minimal sample manipulation, is unaffected by adsorption of interfering species at the electrode surface and allows direct determination of free zinc ion concentrations. Therefore AGNES results can be used in conjunction with ecotoxicological studies and speciation modelling to set and test compliance with water quality standards.
Is part of
Analytica Chimica Acta, 2016, vol. 912, p. 32-40European research projects
Collections
The following license files are associated with this item:
Related items
Showing items related by title, author, creator and subject.
-
Determination of free Zn2+ concentration in synthetic and natural samples with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) and DMT (Donnan Membrane Technique)
Chito Trujillo, Diana Maria; Weng, Liping; Galceran i Nogués, Josep; Companys Ferran, Encarnació; Puy Llorens, Jaume; Riemsdijk, Willem H. van; Leeuwen, Herman P. van (Elsevier, 2012-04-01)The determination of free Zn2+ ion concentration is a key in the study of environmental systems like river water and soils, due to its impact on bioavailability and toxicity. AGNES (Absence of Gradients and Nernstian ... -
A comparison between the determination of free Pb(II) by two techniques: Absence of gradients and Nernstian equilibrium stripping and resin titration
Alberti, Giancarla; Biesuz, Raffaela; Huidobro Redondo, César; Companys Ferran, Encarnació; Puy Llorens, Jaume; Galceran i Nogués, Josep (Elsevier, 2007)Absence of gradients and Nernstian equilibrium stripping (AGNES) is an emerging electroanalytical technique designed to measure free metal ion concentration. The practical implementation of AGNES requires a critical selection ... -
Determination of the complexing capacity of synthetic and real wine for Zn using Absence of Gradients and Nerstian Equilibrium Stripping technique
Chito Trujillo, Diana Maria; Galceran i Nogués, Josep; Companys Ferran, Encarnació; Puy Llorens, Jaume (American Chemical Society, 2013-02-06)The complexing capacity of synthetic (0.011 M tartrate in 13.5% ethanol) and real wine (Raimat Abadia) in titrations with added total Zn concentrations up to 0.03 M has been determined following the free Zn concentrations ...